from fastapi import APIRouter, HTTPException
from typing import List, Optional
from pydantic import BaseModel

router = APIRouter()

class Item(BaseModel):
    id: int
    name: str
    description: Optional[str] = None
    price: float
    in_stock: bool = True

# 模拟数据
items_db = [
    Item(id=1, name="商品1", description="这是商品1", price=99.99, in_stock=True),
    Item(id=2, name="商品2", description="这是商品2", price=199.99, in_stock=False),
    Item(id=3, name="商品3", price=299.99, in_stock=True),
]

@router.get("/items", response_model=List[Item])
def get_all_items():
    """获取所有商品"""
    return items_db

@router.get("/items/{item_id}", response_model=Item)
def get_item(item_id: int):
    """根据ID获取商品"""
    for item in items_db:
        if item.id == item_id:
            return item
    raise HTTPException(status_code=404, detail="商品未找到")

@router.post("/items", response_model=Item)
def create_item(item: Item):
    """创建新商品"""
    # 检查ID是否已存在
    for existing_item in items_db:
        if existing_item.id == item.id:
            raise HTTPException(status_code=400, detail="商品ID已存在")

    items_db.append(item)
    return item

@router.put("/items/{item_id}", response_model=Item)
def update_item(item_id: int, item: Item):
    """更新商品"""
    for index, existing_item in enumerate(items_db):
        if existing_item.id == item_id:
            items_db[index] = item
            return item
    raise HTTPException(status_code=404, detail="商品未找到")

@router.delete("/items/{item_id}")
def delete_item(item_id: int):
    """删除商品"""
    for index, item in enumerate(items_db):
        if item.id == item_id:
            del items_db[index]
            return {"message": "商品已删除"}
    raise HTTPException(status_code=404, detail="商品未找到")